Short definition: A METAR is a standardised aviation weather report that describes the observed conditions at an aerodrome at a specific time.
Detailed explanation: METARs are issued at regular intervals, usually every hour or half-hour, and use a fixed format so pilots and dispatchers can read weather quickly and consistently. A typical METAR includes the aerodrome identifier, time of observation, wind direction and speed, visibility, present weather, cloud, temperature, dew point, and altimeter setting or QNH. Some reports also include recent weather, wind gusts, variable wind, runway visual range, or significant remarks. Because a METAR reports observed conditions rather than a forecast, it is mainly used to assess the current weather at departure, destination, or alternate aerodromes.
Key considerations:
- A METAR only reflects conditions at the time of observation and may not show rapid changes between reports.
- A common mistake is confusing a METAR with a TAF, which is a forecast rather than an observation.
- In real operations, METAR data affects runway selection, fuel planning, alternate requirements, and approach suitability.
Further Reading: Live METARs – Aviation Weather Center | METAR – Wikipedia
